Rook checks for down OSDs by checking the `ReadyReplicas` count
in the OSD deployement. When an OSD pod goes into CBLO due to
disk failure, there is a delay before this `ReadyReplicas` count
becomes 0. The deplay is very small but may result in rook missing
OSD down event. As a result no blocking PDBs will be created and
only default PDB with `AllowedDisruptions` count as 0 is available.
This PR tries to solve this. The OSD pdb reconciler will be
reconciled again if `AllowedDisruptions` count in the main
PDB is 0.
Signed-off-by: Santosh Pillai <sapillai@redhat.com>